(Nitrogen-Vacancy)-Complex Formation in SiC: Experiment and Theory
Nitrogen (N) donors in SiC are partially deactivated either by Si+-/N+-co-implantation or by irradiation with electrons of 200 keV energy and subsequent annealing at temperatures above 1450°C; simultaneously the compensation is decreased. The free electron concentration and the formation of energetically deep defects in the processed samples are determined by Hall effect and deep level transient spectroscopy. A detailed theoretical treatment based on the density functional theory is conducted; it takes into account the kinetic mechanisms for the formation of N interstitial clusters and (N-vacancy)-complexes. This analysis clearly indicates that the (NC)4-VSi complex, which is thermally stable up to high temperatures and which has no level in the band gap of 4HSiC, is responsible for the N donor deactivation.
N. Wright, C.M. Johnson, K. Vassilevski, I. Nikitina and A. Horsfall
G. Pensl et al., "(Nitrogen-Vacancy)-Complex Formation in SiC: Experiment and Theory", Materials Science Forum, Vols. 556-557, pp. 307-312, 2007